Dockerfile Cheatsheet

Dockerfile

# Stage for image creation for production
FROM maven:3-jdk-8 as builder

WORKDIR /app

# Setting the project's working directory for dependency installation
COPY application .

# Installing dependencies
RUN mvn -DskipTests=true clean
RUN mvn -DskipTests install

# Creating the "/app-jar-output" directory and copying the ".jar" file of this project with included dependencies
RUN mkdir /app-jar-output
RUN cp /app/target/*with-dependencies.jar /app-jar-output

# Stage for image creation for production
FROM openjdk:8-jre-slim-buster

# Setting the project's working directory
WORKDIR /app

# Fixing timezone (tzdata) for the container and upgrading to update the Java, which in turn updates its internal timezone. It's not ideal, but it resolves the issue.
RUN apt-get update -y &&\
    apt-get --only-upgrade install tzdata -y
    # apt-get install tzdata-java -y

# Copying the ".jar" file from the builder stage of the application
COPY --from=builder /app-jar-output/ .

# Running the application. The "*" is adopted to allow reusability of this Dockerfile in other applications since no fixed values are provided.
CMD /usr/local/openjdk-8/bin/java $JAVA_OPTS -jar $(ls *.jar)